1. Field of the Present Disclosure
The present disclosure relates to an image processing apparatus and an image scanning apparatus.
2. Description of the Related Art
When an image of a book, particularly a thick book having a lot of pages is scanned using an image scanning apparatus such as a copier or a scanner, the book is put on a platen glass so as to open the book at a desired page and the page is scanned. In that time, if a binding part of the book is away over the platen glass, a noise appears as black pixels at the binding part in a document image. Such noise is unnecessary to a user, and therefore, it is favorable that such noise is eliminated automatically.
An image scanning apparatus (a) derives values obtained by integrating densities along a coordinate substantially parallel to a binding part in a document image at each position along a coordinate substantially perpendicular to the binding part, (b) generates a spatial frequency distribution by performing Fourier transformation of a distribution of the values, and (c) cancels a noise and detects the binding part by performing inverse Fourier transformation of a peak part in the spatial frequency distribution.
However, in the aforementioned technique, the Fourier transformation and the inverse Fourier transformation must be performed to detect the binding part (i.e. the binding part in the document image), and consequently, since complicated computation is required, it results in large circuit scale, long computation time, and so forth.